1. Field of the Invention
The present invention relates a process for preparing polymers. The present invention particularly relates to a process for preparing polymers employing on-line analyzers.
2. Background of the Art
Laboratory analysis of production samples during the production of chemical products, and especially when those products are polymers, is a necessary part of the production process. The purposes for these analyses include process control and to ensure product quality, especially during transitions between product grades.
Such chemical analyses can be off-line or on-line. An off-line analysis is accomplished by taking a sample of a process stream and then subjecting it to a laboratory analysis. An on-line analysis is usually accomplished by conducting a portion of the process stream directly to a chemical process analyzer such as an on-line gas chromatograph or by using a probe or other device that can be inserted directly into the process stream. For example, a pH or corrosion probe could be inserted directly into a process stream. On-line chemical process analyzers can offer significant advantages in reducing sample analysis time, which can in turn improve product quality and reduce costs by means of reducing waste in the form of off specification product or prevent premature maintenance which has both direct and indirect costs to chemical manufacturers.
The use of on-line analyzers is known. For example, U.S. Pat. No. 4,370,201 to Lowenhaupt discloses an on-line FTIR process for maintaining coal proportions in a coal blend. U.S. Pat. No. 4,743,339 to Faix, et al., discloses an off-line FTIR process for controlling the digestion of wood pulp. U.S. Pat. No. 5,151,474 to Lange, et al., discloses the use of an FTIR in the production of polyolefins.